[HELP] Applying Motion Capture to UE4 Mannequin

Hi guys and girls,

I’m wondering after a week of trying if there’s something I’m missing. I’m trying to apply Motion Capture Data to the UE4 Mannequin Skeleton and I managed to somehow do it before by merging the mesh with the fbx in Motion Builder but for some reason it’s not working now and I can’t for the life of me remember what I did differently.
Does anyone know a way I can do it? I’m used to Biped and not Bones so there may be something really easy I’m missing.
Any help would be extremely appreciated as I seem to have hit a wall with this.

I’m relativity new to UE4 so sorry if this is a simple fix!

Thanks a lot.